This invention relates to a fluid sample transport device with a reduced dead volume for processing, controlling and/or detecting a fluid sample. This invention relates in particular to a molecular diagnostic application with a reduced dead volume. The fluid sample transport device with reduced dead volume according to the present invention is preferably used in molecular diagnostics.
The biotechnology sector has directed substantial effort towards developing miniaturized fluid sample transport devices such as microfluidic devices, often termed labs-on-a-chip (LOC) or micro total analyses systems (microTAS), for sample manipulation and analysis. These systems are used for detection and analyses of specific bio-molecules, such as DNA and proteins.
In general micro-system devices contain fluidic, electrical and mechanical functions, comprising pumps, valves, mixers, heaters, and sensors such as optical-, magnetic- and/or electrical sensors. A typical molecular diagnostic assay includes process steps such as cell lyses, washing, amplification by PCR, and/or detection.
Integrated microfluidic devices need to combine a number of functions, like filtering, mixing, fluid actuation, valving, heating, cooling and optical, electrical or magnetic detection, on a single template. Following a modular concept the different functions can be realised on separate functional substrates, like silicon or glass. The functions need to be assembled with a microfluidic channel system, which is typically made of plastic. With small channel geometries this way of integration becomes a very challenging process. The interfaces between the substrates and the channel plate need to be very smooth and accurate, and the channel geometries need to be reproducible, while the functional substrates should have a minimum footprint for cost efficiency. Especially with functions, which need a fluidic as well as an electric interface, the separation of the wet interface is critical. Bonding techniques must be compatible with the biochemical reagents and surface treatments present on the functional substrates.
US-A1 2003/0057391, incorporated by reference, discloses a low power integrated pumping and valving array which provides a revolutionary approach for performing pumping and valving operations in micro fabricated fluidic systems for applications such as medical diagnostic microchips. This approach integrates a lower power, high-pressure source with a polymer, ceramic, or metal plug enclosed within a micro channel, analogous to a micro syringe. When the pressure source is activated, the polymer plug slides within the micro channel, pumping the fluid on the opposite side of the plug without allowing fluid to leak around the plug. The plugs also can serve as micro valves.
However, the pump system of US-A1 2003/0057391 does not provide a sufficient small dead volume and does not provide an optimized fast fluid transport. Further, the plugs must have a positive fitting to avoid sample fluid leakage thus the low power integrated pumping and valving arrays can not be provided at low vertical range of manufacture.
In the last decade, considerable research efforts have been made to the development of microfluidic system devices in order to integrate more functions but at the same time reducing the analyze samples volumes of liquid.
Despite this effort, there is still a need for a fluid sample transport devices such as a microfluidic system device, microfluidic bio chips, often termed Bio Flips, LOCs and microTASs, to overcome at least one drawback of the prior art mentioned above. Further, there is a need to develop technologies that lead to total integration of peripheral functions onto single microchips, including innovative low power/pressure sources for on-chip fluidic manifolds that allows analyzing samples in small volumes of liquid as well as providing more economical use of reagents and samples. In particular there is a need for a fluid sample transport device with an optimized reduced dead volume to a minimum.